Hyaloclastite pozzolan, hyaloclastite based cement, hyaloclastite based concrete and method of making and using same

ABSTRACT

The invention comprises a composition comprising hyaloclastite having a volume-based mean particle size of less than or equal to 40 μm. The invention also comprises a cementitious material comprising a hydraulic cement and hyaloclastite, wherein the hyaloclastite has a volume-based mean particle size of less than or equal to approximately 40 μm. The invention further comprises a cementitious-based material comprising aggregate, a cementitious material comprising a hydraulic cement and hyaloclastite, wherein the hyaloclastite has a volume-based mean particle size of less than or equal to approximately 40 μm and water sufficient to hydrate the cementitious material. A method of using the composition of the present invention is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/817,458filed Nov. 20, 2017 now U.S. patent Ser. No. 10,047,006, which is acontinuation of application Ser. No. 15/595,411 filed May 15, 2017, nowU.S. Pat. No. 9,822,037 and a continuation of application Ser. No.15/595,430 filed May 15, 2017, now U.S. Pat. No. 9,828,289.

FIELD OF THE INVENTION

The present invention generally relates to a natural pozzolan. Moreparticularly, the present invention relates to a cementitious materialcontaining hyaloclastite. The present invention further relates toconcrete or mortar containing hyaloclastite or a cementitious materialthat contains hyaloclastite. The present invention also relates to amethod of making a hyaloclastite-based cementitious material. Thepresent invention further relates to a method a making concrete with ahydraulic cement and a hyaloclastite-based pozzolan. The presentinvention further relates to a method of making concrete or mortar withportland cement and a hyaloclastite-based pozzolan. The presentinvention also relates to a method of making concrete comprising acementitious material based on hyaloclastite. In addition, the presentinvention relates to a method of curing concrete comprising ahyaloclastite-based pozzolan or a hyaloclastite-based cementitiousmaterial.

BACKGROUND OF THE INVENTION

Concrete dates back at least to Roman times. The invention of concreteallowed the Romans to construct building designs, such as arches, vaultsand domes, that would not have been possible without the use ofconcrete. Roman concrete, or opus caementicium, was made from ahydraulic mortar and aggregate or pumice. The hydraulic mortar was madefrom either quicklime, gypsum or pozzolana. Quick lime, also known asburnt lime, is calcium oxide; gypsum is calcium sulfate dihydrate andpozzolana is a fine, sandy volcanic ash (with properties that were firstdiscovered in Pozzuoli, Italy). The concrete made with volcanic ash asthe pozzolanic agent was slow to set and gain strength. Most likely theconcrete was build up in multiple layers on forms that had to stay inplace for a very long time. Although the concrete was slow to set andgain strength, over long periods of time it achieved great strength andwas extremely durable. There are still Roman concrete structuresstanding today as a testimony to the quality of the concrete producedover 2000 years ago.

Modern concrete is composed of one or more hydraulic cements, coarseaggregates, and fine aggregates. Optionally, modern concrete can includeother cementitious materials, inert fillers, property modifyingadmixtures and coloring agents. The hydraulic cement is typicallyportland cement. Other cementitious materials include fly ash, slagcement and other known natural pozzolanic materials. The term “pozzolan”is defined in ACI 116R as, “ . . . a siliceous or siliceous andaluminous material, which in itself possesses little or no cementitiousvalue but will, in finely divided form and in the presence of moisture,chemically react with calcium hydroxide at ordinary temperatures to formcompounds possessing cementitious properties.”

Portland cement is the most commonly used hydraulic cement in use aroundthe world today. Portland cement is typically made from limestone.Concrete or mortar made with portland cement sets relatively quickly andgains relatively high compressive strength in a relatively short time.Although significant improvements have been made to the process andefficiency of portland cement manufacturing, it is still a relativelyexpensive and highly polluting industrial process.

Fly ash is a by-product of the combustion of pulverized coal in electricpower generation plants. When the pulverized coal is ignited in acombustion chamber, the carbon and volatile materials are burned off.When mixed with lime and water, fly ash forms a compound similar toportland cement. Two classifications of fly ash are produced accordingto the type of coal from which the fly ash is derived. Class F fly ashis normally produced from burning anthracite or bituminous coal thatmeets applicable requirements. This class of fly ash has pozzolanicproperties and will have minimum amounts of silica dioxide, aluminumoxide and iron oxide of 70%. Class F fly ash is generally used inhydraulic cement at dosage rates of 15% to 30% by weight, with thebalance being portland cement. Class C fly ash is normally produced fromlignite or subbituminous coal that meets applicable requirements. Thisclass of fly ash, in addition to pozzolanic properties, also has somecementitious properties. Class C fly ash is used in hydraulic cement atdosage rates of 15% to 40% by weight, with the balance being portlandcement.

Recently, the U.S. concrete industry has used an average of 15 milliontons of fly ash at an average portland cement replacement ratio ofapproximately 16% by weight. Since fly ash is a by-product from theelectric power generating industry, the variable properties of fly ashhave always been a major concern to the end users in the concreteindustry. Traditionally, wet scrubbers and flue gas desulfurization(“FGD”) systems have been used to control power plant SO₂ and SO₃emissions. The residue from such systems consists of a mixture ofcalcium sulfite, sulphate, and fly ash in water. In using sodium-basedreagents to reduce harmful emissions from the flue gas, sodium sulfiteand sulfate are formed. These solid reaction products are incorporatedin a particle stream and collected with the fly ash in particulatecontrol devices. There is the potential for the sodium-based reagent toreact with other components of the gas phases and with ash particulatesin the flue gas and in the particulate control device. All of theproducts of these reactions have the potential to impact the resultingfly ash. Anecdotal evidence has shown that the fly ash that containssodium-based components has unpredictable and deleterious effect inconcrete. Consequently, the concrete industry is at great risk of usinga product that is unpredictable in its performance. Coupled with theclosure of many coal-fired power plants, resulting in less availabilityof fly ash, the concrete industry is facing a dramatic shortage of afamiliar pozzolan.

Known natural pozzolans can be used in concrete to replace the growingshortage of fly ash. However, known natural pozzolan deposits arelimited and generally are far from construction markets. Naturalpozzolans can be raw or processed. ASTM C-618 defined Class N naturalpozzolans as, “Raw or calcined natural pozzolans that comply with theapplicable requirements for the class as given herein, such as somediatomaceous earth; opaline chert and shales; tuffs and volcanic ashesor pumicites, any of which may or may not be processed by calcination;and various materials requiring calcination to induce satisfactoryproperties, such as some clays and shales.”

Other known natural pozzolans include Santorin earth, Pozzolana,Trachyte, Rhenish trass, Gaize, volcanic tuffs, pumicites, diatomaceousearth, and opaline shales, rice husk ash and metakaolin. Santorin earthis produced from a natural deposit of volcanic ash of daciticcomposition on the island of Thera in the Agean Sea, also known asSantorin, which was formed about 1600-1500 B.C. after a tremendousexplosive volcanic eruption (Marinatos 1972). Pozzolana is produced froma deposit of pumice ash or tuff comprised of trachyte found near Naplesand Segni in Italy. Pozzolana is a product of an explosive volcaniceruption in 79 A.D. at Mount Vesuvius, which engulfed Herculaneum,Pompeii, and other towns along the bay of Naples. The deposit nearPozzuoli is the source of the term “pozzolan” given to all materialshaving similar properties. Similar tuffs of lower silica content havebeen used for centuries and are found in the vicinity of Rome. In theUnited States, volcanic tuffs and pumicites, diatomaceous earth, andopaline shales are found principally in Oklahoma, Nevada, Arizona, andCalifornia. Rice husk ash (“RHA”) is produced from rice husks, which arethe shells produced during the dehusking of rice. Rice husks areapproximately 50% cellulose, 30% lignin, and 20% silica. Metakaolin(Al₂O₃:2SiO₂) is a natural pozzolan produced by heatingkaolin-containing clays over a temperature range of about 600 to 900° C.(1100 to 1650° F.) above which it recrystallizes, rendering it mullite(Al₆Si₂O₁₃) or spinel (MgAl₂O₄) and amorphous silica (Murat, Ambroise,and Pera 1985). The reactivity of metakaolin is dependent upon theamount of kaolinite contained in the original clay material. The use ofmetakaolin as a pozzolanic mineral admixture has been known for manyyears, but has grown rapidly since approximately 1985.

Natural pozzolans were investigated in this country by Bates, Phillipsand Wig as early as 1908 (Bates, Phillips, and Wig 1912) and later byPrice (1975), Meissner (1950), Mielenz, Witte, and Glantz (1950), Davis(1950), and others. They showed that concretes containing pozzolanicmaterials exhibited certain desirable properties such as lower cost,lower temperature rise, and improved workability. According to Price(1975), an example of the first large-scale use of portland-pozzolancement, composed of equal parts of Portland cement and a rhyoliticpumicite, is the Los Angeles aqueduct in 1910-1912. Natural pozzolans bytheir very definition have high silica or alumina and silica contenteither in a raw or calcined form.

Generally fly ash has the advantage that it can reduce water demand ofthe cementitious matrix. This reduces plastic shrinkage and allows forbetter workability. Generally, known natural pozzolans and silica fumeincrease water demand in the cementitious matrix; in some cases as highas 110%-115% that of portland cement. Greater water demand createsundesirable concrete properties such as lower strength development andgreater plastic shrinkage. It is desired that pozzolans have a waterdemand that is lower than or equal to portland cement. However this isan extremely rare occurrence for known natural pozzolans.

The alkali-silica reaction (“ASR”), more commonly known as “concretecancer”, is a reaction that occurs over time in concrete between thehighly alkaline cement paste and the reactive non-crystalline(amorphous) silica found in many common aggregates, provided there issufficient moisture present. This reaction causes the expansion of thealtered aggregate by the formation of a soluble and viscous gel ofsodium silicate (Na₂SiO₃.n H₂O, also noted Na₂H₂SiO₄.n H₂O, or N—S—H(sodium silicate hydrate), depending on the adopted convention). Thishygroscopic gel swells and increases in volume when absorbing water. Theswelling gel exerts an expansive pressure inside the siliceousaggregate, causing spalling and loss of strength of the concrete,finally leading to its failure. ASR can cause serious cracking inconcrete, resulting in critical structural problems that can even forcethe demolition of a particular structure.

Therefore, it would be desirable to have a natural pozzolan that doesnot need to be calcined to render it active. It would also be desirableto have a natural pozzolan that has a water demand less than or equal toportland cement. It would also be desirable to have a natural pozzolanwith properties as good as or better than fly ash. It would also bedesirable to have a natural pozzolan that reduces ASR in concrete. Itwould be desirable to have a natural pozzolan that has ASR mitigationproperties better than or equal to portland cement. It would also bedesirable to have a natural pozzolan with similar specific gravity asportland cement that can replace portland cement on a one-to-one basis.It would also be desirable to have a natural pozzolan that produce aconcrete with relatively rapid setting and strength gaining properties.It would also be desirable to have a natural pozzolan that when combinedwith portland cement produces a concrete with an ultimate compressivestrength greater than or equal to straight portland cement-basedconcrete.

SUMMARY OF THE INVENTION

The present invention satisfies the foregoing needs by providing anatural pozzolan that has improved properties and lower water demandthan known natural pozzolans.

In one disclosed embodiment, the present invention comprises acomposition. The composition comprises hyaloclastite having avolume-based mean particle size of less than or equal to 40 μm.

In another disclosed embodiment, the present invention comprises acementitious material. The cementitious material comprises a hydrauliccement and hyaloclastite, wherein the hyaloclastite has a volume-basedmean particle size of less than or equal to approximately 40 μm.

In yet another disclosed embodiment, the present invention comprises acementitious-based material. The cementitious-based material comprisesaggregate, a cementitious material comprising a hydraulic cement andhyaloclastite in powder form and water sufficient to hydrate thecementitious material.

In another disclosed embodiment, the present invention comprises amethod. The method comprises combining aggregate, a cementitiousmaterial and water, wherein the cementitious material compriseshydraulic cement and hyaloclastite, wherein the hyaloclastite has avolume-based mean particle size of less than or equal to approximately40 μm.

In another disclosed embodiment, the present invention comprises amethod. The method comprises grinding hyaloclastite rock such that theground hyaloclastite has a volume-based mean particle size ofapproximately 40 μm.

In a further disclosed embodiment, the present invention comprises amethod. The method comprises grinding hyaloclastite rock to a powder andscreening the powder with a 325 mesh screen, wherein approximately 80%to approximately 100% by volume of the powder passes through the screen.

Accordingly, it is an object of the present invention to provide animproved concrete or mortar.

Another object of the present invention is to provide an improvedcementitious material.

A further object of the present invention is to provide an improvedsupplementary cementitious material.

Yet another object of the present invention is to provide a pozzolanwith a lower water demand than portland cement.

Another object of the present invention is to provide a pozzolan with aspecific gravity approximately equal to that of portland cement so thatit can replace portland cement on a one-to-one basis.

Another object of the present invention is to provide an improvednatural pozzolan.

Another object of the present invention is to provide a natural pozzolanthat reduces ASR in concrete.

These and other objects, features and advantages of the presentinvention will become apparent after a review of the following detaileddescription of the disclosed embodiments and the appended claims.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

Hyaloclastite is a hydrated tuff-like breccia typically rich in blackvolcanic glass, formed during volcanic eruptions under water, under iceor where subaerial flows reach the sea or other bodies of water. It hasthe appearance of angular fragments sized from approximately amillimeter to a few centimeters. Larger fragments can be found up to thesize of pillow lava as well. Several minerals are found in hyaloclastitemasses including, but not limited to, sideromelane, tachylite.palagonite, olivine, pyroxene, magnetite, quartz, hornblende, biotite,hypersthene, feldspathoids, plagioclase, calcite and others.Fragmentation can occur by both an explosive eruption process or by anessentially nonexplosive process associated with the spalling of pillowbasalt rinds by thermal shock or chill shattering of molten lava. Thewater-quenched basalt glass is called sideromelane, a pure variety ofglass that is transparent, and lacks the very small iron-oxide crystalsfound in the more common opaque variety of basalt glass calledtachylite. In hyaloclastite, these glassy fragments are typicallysurrounded by a matrix of yellow-to-brown palagonite, a wax-likesubstance that forms from the hydration and alteration of thesideromelane and other minerals. Depending on the type of lava, the rateof cooling and the amount of lava fragmentation, the particle of thevolcanic glass (sideromelane) can be mixed with other volcanic rocks orcrystalline minerals, such as olivine, pyroxene, magnetite, quartz,plagioclase, calcite and others.

Hyaloclastite is usually found within or adjacent subglacial volcanoes,such as tuyas, which is a type of distinctive, flat-topped, steep-sidedvolcano formed when lava erupts under or through a thick glacier or icesheet. Hyaloclastite ridges are also called tindars and subglacialmounds are called tuyas or mobergs. They have been formed by subglacialvolcanic eruptions during the last glacial period. A subglacial mound isa type of subglacial volcano. This type of volcano forms when lavaerupts beneath a thick glacier or ice sheet. The magma forming thesevolcanoes was not hot enough to melt a vertical pipe through theoverlying glacial ice, instead forming hyaloclastite and pillow lavadeep beneath the glacial ice field. Once the glacier retreated, thesubglacial volcano was revealed, with a unique shape as a result of itsconfinement within the glacial ice. Subglacial volcanoes are somewhatrare worldwide, being confined to regions that were formerly covered bycontinental ice sheets and also had active volcanism during the sameperiod. Currently, volcanic eruptions under existing glaciers may createhyaloclastite as well. Hyaloclastite tuff-like breccia is a pyroclasticrock comprised of glassy juvenile clasts contained in a fine-grainedmatrix dominated by glassy shards. Hyaloclastite breccias are typicallyproducts of phreatomagmatic eruptions in particular associated with theeruption of magmas into bodies of water and form by fragmentation ofchilled magma. They are often formed from basaltic magmas and areassociated with pillow lavas and sheet flows. In addition, any othertype of lava, such as intermediate, andesitic, dacitic and rhyolitic,can form hyaloclastite under similar rapid cooling or quenchingconditions.

In lava deltas, hyaloclastite forms the main constituent of foresetsformed ahead of the expanding delta. The foresets fill in the seabedtopography, eventually building up to sea level, allowing the subaerialflow to move forward until it reaches the sea again.

At mid-ocean ridges, tectonic plates diverge, creating fissures on theocean floor. Along these fissures underwater volcanoes erupt forming seamounds that in some places can reach the surface of the water. As thelava erupts underwater, it can be rapidly quenched thereby creatinghyaloclastite. This is an active process especially at hot spots aroundthe world. These hot spots are an important cause of island formation.These islands are a prime sources of hyaloclastite formation.

Volcanic lava eruptions in Hawaii that spill in the ocean are alsorapidly quenched and fragmented thus producing hyaloclastite. The rapidcooling and quenching prevents or reduces lava crystallization thushyaloclastite may have a significant amorphous make up.

Basalt is an aphanitic (fine-grained) igneous rock with generally 43% to53% silica (SiO₂) containing essentially calcic plagioclase feldspar andpyroxene (usually Augite), with or without olivine. Intermediate basalthas generally between 53% to 57% silica (SiO₂) content. Basalts can alsocontain quartz, hornblende, biotite, hypersthene (an orthopyroxene) andfeldspathoids. Basalts are often porphyritic and can contain mantlexenoliths. Basalt is distinguished from pyroxene andesite by its morecalcic plagioclase. There are two main chemical subtypes of basalt:tholeiites which are silica saturated to oversaturated and alkalibasalts that are silica undersaturated. Tholeiitic basalt dominate theupper layers of oceanic crust and oceanic islands, alkali basalts arecommon on oceanic islands and in continental magmatism. Basalts canoccur as both shallow hypabyssal intrusions or as lava flows. Theaverage density basalt is approximately 3.0 gm/cm³.

Andesite is an abundant igneous (volcanic) rock of intermediatecomposition, with aphanitic to porphyritic texture. In a general sense,it is an intermediate type between basalt and dacite, and ranges from57% to 63% silicon dioxide (SiO₂). The mineral assemblage is typicallydominated by plagioclase plus pyroxene or hornblende. Magnetite, zircon,apatite, ilmenite, biotite, and garnet are common accessory minerals.Alkali feldspar may be present in minor amounts.

Dacite is an igneous, volcanic rock with an aphanitic to porphyritictexture and is intermediate in composition between andesite and rhyoliteand ranges from 63% to 69% silicon dioxide (SiO₂). It consists mostly ofplagioclase feldspar with biotite, hornblende, and pyroxene (augiteand/or enstatite). It has quartz as rounded, corroded phenocrysts, or asan element of the ground-mass. The plagioclase ranges from oligoclase toandesine and labradorite. Sanidine occurs, although in smallproportions, in some dacites, and when abundant gives rise to rocks thatform transitions to the rhyolites. The groundmass of these rocks iscomposed of plagioclase and quartz.

Rhyolite is an igneous (volcanic) rock of felsic (silica-rich)composition, typically greater than 69% SiO₂. It may have a texture fromglassy to aphanitic to porphyritic. The mineral assemblage is usuallyquartz, sanidine and plagioclase. Biotite and hornblende are commonaccessory minerals.

Hyaloclastite can be classified based on the amount of silica contentas: basaltic (less than 53% by weight SiO₂), intermediate (approx.53-57% by weight SiO₂), or silicic such as andesitic (approximately57-63% by weight SiO₂), dacitic (approximately by weight 63-69% byweight SiO₂), or rhyolitic (greater than 69% by weight SiO₂). Basaltichyaloclastite can be classified based on alkalinity level as tholeiitic,intermediate and alkaline.

As used herein, the term “hyaloclastite” shall mean hyaloclastite fromany and all sources; i.e., all hyaloclastites irrespective of themineral source from which it is derived.

Hyaloclastite deposits can be found in many places throughout the worldincluding, but not limited to, Alaska, British Columbia, Hawaii,Iceland, throughout the world oceans on seamounts and on oceanic islandsformed at magmatic arcs and tectonic plate rifts by volcanic activity,such as the mid-Atlantic ridge, and others.

In one disclosed embodiment, the present invention compriseshyaloclastite in powder form. The particle size of the hyaloclastitepowder is sufficiently small such that the hyaloclastite powder haspozzolanic properties. The hyaloclastite powder preferably has avolume-based mean particle size of less than or equal to approximately40 more preferably less than or equal to 20 most preferably less than orequal to 15 especially less than or equal to 10 more especially lessthan or equal to 5 The hyaloclastite powder preferably has a Blainevalue of approximately 1,500 to approximately 10,000, more preferablyapproximately 3,500 to approximately 10,000, most preferablyapproximately 4,500 to approximately 10,000, especially approximately6,000 to approximately 10,000. The hyaloclastite powder preferably has aBlaine value of greater than or equal to approximately 10,000. Theforegoing ranges include all of the intermediate values. To achieve thedesired particles size, the hyaloclastite rock can be ground usingconventional rock grinding means including, but not limited to, a ballmill, a roll mill or a plate mill. A particle size classifier can beused in conjunction with the mill to achieve the desired particle size.Equipment for grinding and classifying hyaloclastite to the desiredparticle size is commercially available from, for example, F. L. Smidth,Bethlehem, Pa.; Metso, Helsinki, Finland and others. The groundhyaloclastite powder is then preferably classified by screening thepowder with a 325 mesh screen or sieve. Preferably approximately 80% byvolume of the hyaloclastite powder passes through a 325 mesh screen,more preferably approximately 85% by volume of the hyaloclastite powderpasses through a 325 mesh screen, most preferably approximately 90% byvolume of the hyaloclastite powder passes through a 325 mesh screen,especially approximately 95% by volume of the hyaloclastite powderpasses through a 325 mesh screen and more especially approximately 100%by volume of the hyaloclastite powder passes through a 325 mesh screen.Preferably approximately 80% to approximately 100% by volume of thehyaloclastite powder passes through a 325 mesh screen, more preferablyapproximately 90% to approximately 100% by volume of the hyaloclastitepowder passes through a 325 mesh screen, most preferably approximately95% to approximately 100% by volume of the hyaloclastite powder passesthrough a 325 mesh screen, especially approximately 100% by volume ofthe hyaloclastite powder passes through a 325 mesh screen. The foregoingranges include all of the intermediate values. Preferably a maximum of34% by volume of the hyaloclastite powder is retained on the 325 meshscreen, more preferably a maximum of approximately 20% by volume of thehyaloclastite powder is retained on the 325 mesh screen, most preferablya maximum of approximately 10% by volume of the hyaloclastite powder isretained on the 325 mesh screen, especially a maximum of approximately5% by volume of the hyaloclastite powder is retained on the 325 meshscreen, more especially approximately 0% by volume of the hyaloclastitepowder is retained on the 325 mesh screen. The foregoing percentagesinclude all of the intermediate values.

In another disclosed embodiment, the hyaloclastite rock can beinterground with hydraulic cement clinker. For example, hyaloclastiterock can be interground with portland cement clinker or slag cementclinker. That is hyaloclastite rock and portland cement clinker can becombined and ground at the same time with the same equipment.

In one disclosed embodiment of the present invention, the hyaloclastitepreferably has a chemical composition of approximately 43% toapproximately 57% by weight SiO₂, approximately 5% to approximately 20%by weight Al₂O₃, approximately 8% to approximately 15% by weight Fe₂O₃,approximately 5% to approximately 15% by weight CaO, approximately 5% toapproximately 15% by weight MgO, less than or equal to approximately 3%by weight Na₂O. In addition to the foregoing, other compounds can bepresent in small amounts, such as K₂O, TiO₂, P₂O₅, MnO, various metals,rare earth trace elements and other unidentified elements. Whencombined, these other compounds represent less than 10% by weight of thetotal chemical composition of the hyaloclastite mineral.

In another disclosed embodiment, the hyaloclastite in accordance withthe present invention preferably has a density or specific gravity ofapproximately 2.8 to approximately 3.1.

Hyaloclastite in accordance with the present invention can be incrystalline or amorphous (glassy) form and is usually found as acombination of both in varying proportions. Preferably, thehyaloclastite in accordance with the present invention comprisesapproximately 0% to 99% by weight amorphous form, more preferablyapproximately 10% to approximately 80% by weight amorphous form, mostpreferably approximately 20% to approximately 60% by weight amorphousform, especially approximately 30% to approximately 50% by weightamorphous form. The crystalline portion of hyaloclastite preferablycomprises approximately 3% to approximately 20% by weight olivine,approximately 5% to approximately 40% by weight clinopyroxene,approximately 5% to approximately 60% by weight plagioclase, andapproximately 0% to approximately 10% (or less than 10%) by weight otherminerals including, but not limited to, magnetite, UlvoSpinel, quartz,feldspar, pyrite, illite, hematite, chlorite, calcite, hornblende,biotite, hypersthene (an orthopyroxene), feldspathoids sulfides, metals,rare earth minerals, other unidentified minerals and combinationsthereof. The foregoing ranges include all of the intermediate values.

Hyaloclastite in accordance with the present invention can be used as asupplementary cementitious material in concrete or mortar mixes.Hyaloclastite in accordance with the present invention is not by itselfa hydraulic cement, but is activated by CaOH (hydrate lime) produced bythe hydration of hydraulic cements, such as portland cement, or by otherminerals or compounds having reactive hydroxyl groups, such as CaO(quick lime). In addition hyaloclastite in accordance with the presentinvention when mixed with cement may improve the cement nucleationprocess thereby improving the cement hydration process. Hyaloclastite infiner particles generally yields shorter set times and accelerateshydration in blended cements. Finer particle size hyaloclastiteincreases the rate of hydration heat development and early-agecompressive strength in portland cement. This acceleration may beattributable to the hyaloclastite particle size (nucleation sites), itscrystalline make-up and/or chemical composition. Hyaloclastite inaccordance with the present invention can be used in combination withany hydraulic cement, such as portland cement. Other hydraulic cementsinclude, but are not limited to, blast granulated slag cement, calciumaluminate cement, belite cement (dicalcium silicate), phosphate cementsand others. Also, hyaloclastite in accordance with the present inventionby itself can be blended with lime to form a cementitious material. Inone disclosed embodiment, blended cementitious material for cement ormortar preferably comprises approximately 10% to approximately 90% byweight hydraulic cement and approximately 10% to approximately 90% byweight hyaloclastite in accordance with the present invention, morepreferably approximately 20% to approximately 80% by weight hydrauliccement and approximately 20% to approximately 80% by weighthyaloclastite in accordance with the present invention, most preferablyapproximately 30% to approximately 70% by weight hydraulic cement andapproximately 30% to approximately 70% by weight hyaloclastite inaccordance with the present invention, especially approximately 40% toapproximately 60% by weight hydraulic cement and approximately 40% toapproximately 60% by weight hyaloclastite in accordance with the presentinvention, more especially approximately 50% by weight hydraulic cementand approximately 50% by weight hyaloclastite in accordance with thepresent invention, and most especially approximately 70% by weighthydraulic cement and approximately 30% by weight hyaloclastite inaccordance with the present invention. In another disclosed embodimentof the present invention, cementitious material for concrete or mortarpreferably comprises approximately 50% to approximately 90% by weighthydraulic cement and approximately 10% to approximately 50% by weighthyaloclastite in accordance with the present invention. The foregoingranges include all of the intermediate values.

The present invention can be used with conventional concrete mixes.Specifically, a concrete mix in accordance with the present inventioncomprises cementitious material, aggregate and water sufficient tohydrate the cementitious material. The cementitious material comprises ahydraulic cement and hyaloclastite in accordance with the presentinvention. The amount of cementitious material used relative to thetotal weight of the concrete varies depending on the application and/orthe strength of the concrete desired. Generally speaking, however, thecementitious material comprises approximately 6% to approximately 30% byweight of the total weight of the concrete, exclusive of the water, or200 lbs/yd³ (91 kg/m³) of cement to 1,200 lbs/yd³ (710 kg/m³) of cement.In ultra high performance concrete, the cementitious material may exceed25%-30% by weight of the total weight of the concrete. Thewater-to-cement ratio by weight is usually approximately 0.25 toapproximately 0.7. Relatively low water-to-cement materials ratios byweight lead to higher strength but lower workability, while relativelyhigh water-to-cement materials ratios by weight lead to lower strength,but better workability. For high performance concrete and ultra highperformance concrete, lower water-to-cement ratios are used, such asapproximately 0.20 to approximately 0.25. Aggregate usually comprises70% to 80% by volume of the concrete. In ultra high performanceconcrete, the aggregate can be less than 70% of the concrete by volume.However, the relative amounts of cementitious material to aggregate towater are not a critical feature of the present invention; conventionalamounts can be used. Nevertheless, sufficient cementitious materialshould be used to produce concrete with an ultimate compressive strengthof at least 1,000 psi, preferably at least 2,000 psi, more preferably atleast 3,000 psi, most preferably at least 4,000 psi, especially up toabout 10,000 psi or more. In particular, ultra high performanceconcrete, concrete panels or concrete elements with compressivestrengths of over 20,000 psi can be cast and cured using the presentinvention.

The aggregate used in the concrete in accordance with the presentinvention is not critical and can be any aggregate typically used inconcrete. The aggregate that is used in the concrete depends on theapplication and/or the strength of the concrete desired. Such aggregateincludes, but is not limited to, fine aggregate, medium aggregate,coarse aggregate, sand, gravel, crushed stone, lightweight aggregate,recycled aggregate, such as from construction, demolition and excavationwaste, and mixtures and combinations thereof.

The reinforcement of the concrete in accordance with the presentinvention is not a critical aspect of the present invention, and, thus,any type of reinforcement required by design requirements can be used.Such types of concrete reinforcement include, but are not limited to,deformed steel bars, cables, post tensioned cables, pre-stressed cables,fibers, steel fibers, mineral fibers, synthetic fibers, carbon fibers,steel wire fibers, mesh, lath, and the like.

The preferred cementitious material for use with the present inventioncomprises portland cement. The cementitious material preferablycomprises a reduced amount of portland cement and an increased amount ofsupplementary cementitious materials; i.e., hyaloclastite in accordancewith the present invention. This results in cementitious material andconcrete that is more environmentally friendly. The portland cement canalso be replaced, in whole or in part, by one or more pozzolanicmaterials. Portland cement is a hydraulic cement. Hydraulic cementsharden because of a hydration process; i.e., a chemical reaction betweenthe anhydrous cement powder and water. Thus, hydraulic cements canharden underwater or when constantly exposed to wet weather. Thechemical reaction results in hydrates that are substantiallywater-insoluble and so are quite durable in water. Hydraulic cement is amaterial that can set and harden submerged in water by forming insolubleproducts in a hydration reaction. Other hydraulic cements useful in thepresent invention include, but are not limited to, calcium aluminatecement, belite cement (dicalcium silicate), phosphate cements andanhydrous gypsum. However, the preferred hydraulic cement is portlandcement.

In a disclosed embodiment of the present invention, concrete or mortarcomprises a hydraulic cement, hyaloclastite in accordance with thepresent invention, aggregate and water. Preferably, the cementitiousmaterial used to form the concrete or mortar comprises portland cementand hyaloclastite powder, more preferably portland cement andhyaloclastite having a volume-based mean particle size of less than orequal to approximately 40 μm, most preferably portland cement andhyaloclastite having a volume average particle size of less than orequal to approximately 20 μm, especially less than or equal to 15 μm,more especially less than or equal to 10 μm, most especially less thanor equal to 5 μm. In simple terms, the hyaloclastite is reduced to afine powder. The foregoing ranges include all of the intermediatevalues.

In another disclosed embodiment of the present invention, concreteincluding hyaloclastite in accordance with the present invention caninclude any other pozzolan in combination with hydraulic cement.

The portland cement and hyaloclastite in accordance with the presentinvention can be combined physically or mechanically in any suitablemanner and is not a critical feature of the present invention. Forexample, the portland cement and hyaloclastite in accordance with thepresent invention can be mixed together to form a uniform blend of drycementitious material prior to combining with the aggregate and water.Or, the portland cement and hyaloclastite in accordance with the presentinvention can be added separately to a conventional concrete mixer, suchas a transit mixer of a ready-mix concrete truck, at a batch plant. Thewater and aggregate can be added to the mixer before the cementitiousmaterial, however, it is preferable to add the cementitious materialfirst, the water second, the aggregate third and any makeup water last.

Chemical admixtures can also be used with the concrete in accordancewith the present invention. Such chemical admixtures include, but arenot limited to, accelerators, retarders, air entrainments, plasticizers,superplasticizers, coloring pigments, corrosion inhibitors, bondingagents and pumping aid.

Mineral admixtures can also be used with the concrete in accordance withthe present invention. Although mineral admixtures can be used with theconcrete of the present invention, it is believed that mineraladmixtures are not necessary. However, in some embodiments it may bedesirable to include a water reducing admixture, such as asuperplasticizer.

Concrete can also be made from a combination of portland cement andpozzolanic material or from pozzolanic material alone. There are anumber of pozzolans that historically have been used in concrete. Apozzolan is a siliceous or siliceous and aluminous material which, initself, possesses little or no cementitious value but which will, infinely divided form and in the presence of water, react chemically withcalcium hydroxide at ordinary temperatures to form compounds possessingcementitious properties (ASTM C618). The broad definition of a pozzolanimparts no bearing on the origin of the material, only on its capabilityof reacting with calcium hydroxide and water. The general definition ofa pozzolan embraces a large number of materials, which vary widely interms of origin, composition and properties The most commonly usedpozzolans today are industrial by-products, such as slag cement (groundgranulated blast furnace slag), fly ash, silica fume from siliconsmelting, and natural pozzolans such as highly reactive metakaolin, andburned organic matter residues rich in silica, such as rice husk ash.

Hyaloclastite in accordance with the present invention is a previouslyunknown natural pozzolan. It can be used as a substitute for any otherpozzolan or in combination with any one or more pozzolans that are usedin combination with any hydraulic cement used to make concrete ormortar.

It is specifically contemplated as a part of the present invention thatconcrete formulations including hyaloclastite in accordance with thepresent invention can be used with concrete forms or systems that retainthe heat of hydration to accelerate the curing of the concrete.Therefore, in another disclosed embodiment of the present invention,concrete in accordance with the present invention can be cured usingconcrete forms such as disclosed in U.S. Pat. Nos. 8,555,583; 8,756,890;8,555,584; 8,532,815; 8,877,329; 9,458,637; 8,844,227 and 9,074,379 (thedisclosures of which are all incorporated herein by reference);published patent application Publication Nos. 2014/0333010; 2014/0333004and 2015/0069647 (the disclosures of which are all incorporated hereinby reference) and U.S. patent application Ser. No. 15/418,937 filed Jan.30, 2017 (the disclosure of which is incorporated herein by reference).

The following examples are illustrative of selected embodiments of thepresent invention and are not intended to limit the scope of theinvention.

Example 1

The hyaloclastite in accordance with the present invention has theunexpected property of reduced water demand of the cementitious matrix.For example, the water demand of other pozzolans is higher. As anexample, metakaolin's water demand is greater than portland cement whentested in accordance to ASTM C-618; i.e., water requirement as a percentof control is greater than 100. As shown in Table 1 below, pumice (anatural pozzolan) and comparable particle size to hyaloclastite inaccordance with the resent invention had a water demand greater thanportland cement. However, hyaloclastite in accordance with the presentinvention and having a mean particle size of 14 μm when tested inaccordance with the ASTM C 311 and ASTM C-618 had a water requirement of97% when compared with the portland cement control sample. Thehyaloclastite in accordance with the present invention of mean particlesize of 8 μm when tested in accordance with the ASTM C-618 had a waterrequirement of 96% when compared with the portland cement controlsample. The hyaloclastite in accordance with the present inventionhaving a mean particle size of 4 μm when tested in accordance with theASTM C-618 had a water requirement of 97% when compared with theportland cement control sample. When tested in accordance to ASTM-618the hyaloclastite had significantly lower water demand than pumice orportland cement. The water demand of each type is show in Table 1 below.

TABLE 1 ASTM C-618 Water requirement test results compared to controlsample Total Water (SiO₂ + Requirement SiO₂ Al₂O₃ Fe₂O₃ Al₂O₃ + (TestH₂O/ Product type (%) (%) (%) Fe₂O₃ Control H₂O) Pumice 64.30 15.17 7.8987.36 103% (14 μm, d50) Hyaloclastite 46.99 12.15 12.13 71.28  97% (14μm, d50) Pumice 63.57 15.23 7.82 86.62 103%  (8 μm, d50) Hyaloclastite47.20 12.49 12.04 71.73  95%  (8 μm, d50) Hyaloclastite 47.20 12.4912.04 71.73  97%  (4 μm, d50)

Example 2

Hyaloclastite in accordance with the present invention has theunexpected property of significantly reducing ASR in concrete. Testspecimens were prepared in accordance with the procedures described inASTM C441 as modified by ASTM C311. Three control mortar bars were eachprepared from a control mix and three test mortar bars were eachprepared from a test mix using the modified proportions specified byASTM C311. The mix proportions are listed in Table 2 below.

TABLE 2 Mix Proportions Control Mix Test Mix Cemex Cement, g 400 0Lehigh Cement, g 0 300 Hyaloclastite (8 μm, d50), g 0 100 Graded PyrexGlass, g 900 900 Water, ml 226 213 Flow (100-115%) 115 102

As required by ASTM C311, the cement for the control mixture had analkali content less than 0.60% (as equivalent Na₂O) and the cement usedin the test mixture had an alkali content greater than that of thecement used in the control mixture. Cemex cement with an equivalent Na₂Oof 0.30% was used for the control mixtures and Lehigh cement with anequivalent Na₂O of 0.61% was used for the test mixture. A sufficientamount of water was used to produce a flow of 100% to 115%. Thespecimens were cured in a moist room for 24 hours and then stored in amoist container as specified in ASTM C227-10 Standard Test Method forPotential Alkali Reactivity of Cement-Aggregate Combinations (Mortar-BarMethod) at 38° C.±2° C. for 14 days. Results of the testing are reportedin Table 3 below.

TABLE 3 ASR Test Results Length Length (inches) Change Initial 14 Days(%) Control 1 0.0463 0.0487    0.022    Control 2 0.0528 0.0546   0.016    Control 3 0.0542 0.0439    0.018    Average    0.019   Longview 1 0.0464 0.0463  −0.003    Longview 2 0.0456 0.0452  −0.006   Longview 3 0.0443 0.0439  −0.006    Reference 0.0436 0.0438 — Average −0.005    Reduction of Mortar Expansion as % of   126.3%  Control

When tested in accordance to the ASTM C441-11, the test bars showed areduction of Mortar Bar Expansion of 126.3% when compared to the controlbar. Typical Fly Ash Mortar Bar Expansion reduction when tested inaccordance with ASTM C441-11 is approximately 60%-75%. Thus,hyaloclastite in accordance with the present invention reduces ASR muchbetter than fly ash.

Example 3

Hyaloclastite in accordance with the present invention has theunexpected property of improved strength development. Test specimenswere prepared in accordance with the procedures described in ASTM C311and tested in accordance with ASTM C618. Control mortar samples wereeach prepared from a control mix and mortar samples of pumice of 14 μmand 8 μm average mean particle size and hyaloclastite of 14 μm, 8 μm and4 μm average mean particle size in accordance with the presentinvention. These mortar cubes samples were each prepared from a test mixusing the modified proportions specified by ASTM C311 and tested inaccordance with ASTM C618. Sufficient samples we made and testing wasconducted at 1, 3, 7, 14, 28 and 56 days. In order to pass ASTM C618, anatural pozzolan must have a minimum of 75% strength gain at 7 and 28days when compared to the portland cement sample. As shown below,hyaloclastite in accordance with the present invention performed betterthan pumice at each of these intervals. Surprisingly, while pumice at 8μm mean particle size developed lower compressive strength than pumiceat 14 μm mean particle size; whereas, hyaloclastite at 8 μm meanparticle size developed higher compressive strength than hyaloclastiteat 14 μm mean particle size. Over time hyaloclastite in accordance withthe present invention had similar or better compressive strength testresults than the portland cement control samples. Results are of thesetests are shown in Table 4 and 5 below.

TABLE 4 ASTM C-618 Mortar Cube Testing results Compression PSI PumicePumice Hyaloclastite Hyaloclastite Hyaloclastite Control Control Control(14 μm, (8 μm, (14 μm, (8 μm, (4 μm, Test #1 #2 #3 d50) d50) d50) d50)d50)  1 Day 2850 2980 2170 2450 2510 2620  3 Day 4840 4610 3300 36203710 4160  7 Day 4680 5150 3750 3360 3960 4240 5060 14 Day 5520 56304430 4130 4770 5760 28 Day 5640 6350 5180 4610 5280 5530 7030 56 Day6410 6060 5540 5570 5700 6670

TABLE 5 Percentage strength gain (test sample/control sample) SAI %Pumice Pumice (14 μm, (8 μm, Hyaloclastite Hyaloclastite HyaloclastiteTest d50) d50) (14 μm, d50) (8 μm, d50) (4 μm, d50)  1 Day 76 82 84 88 3 Day 68 79 80 90  7 Day 80 72 85 91 98 14 Day 80 73 85 102 28 Day 9282 94 98 111 56 Day 86 92 94 110

The foregoing tests demonstrate that hyaloclastite in accordance withthe present invention unexpectedly produces greater compressive strengthgain than pumice (a natural pozzolan) and the portland cement controlsamples.

Example 4

The specific gravity of portland cement is 3.1. The specific gravity ofpozzolans varies from 2.05 to 2.65. Table 6 below shows the specificgravity for portland cement, hyaloclastite, pumice, dacite, rhyolite,fly ash, matakaolin and nano silica.

TABLE 6 Specific Gravity comparison Product type Specific GravityPortland Cement 3.10 Hyaloclastite 2.8-3.0 Pumice 2.3-2.6 Dacite 2.6-2.7Rhyolite 2.7-2.8 Fly Ash 2.03-2.6  Metakaolin 2.5-2.6 Nanosilioca 2.20

When pozzolans are used to replace portland cement, the ratio ofreplacement takes into consideration specific gravity. Since allpozzolans have a lower specific gravity than portland cement, thepozzolan's replacement weight must be adjusted according to thedifference in the density. Accordingly, known pozzolan replacementratios are often greater than 1 and sometimes as high as 1.3.Hyaloclastite in accordance with the present invention has a specificgravity of 2.90-3.0. Therefore, the replacement ratio of hyaloclastitein accordance with the present invention for portland cement can beone-to-one, thereby saving material and costs.

Example 5

The particle size of hyaloclastite in accordance with the presentinvention was analyzed using a MICROTRAC-X100 light scattering particlessize measuring equipment. The particles were measure in isopropylalcohol, had a reflective index of 1.38, a load factor of 0.0824 and atransmission of 0.87. Table 7 below shows a summary of the particlessize analysis for a hyaloclastite sample wherein 85% by volume of theparticles passed through a 325 mesh screen.

TABLE 7 Property Value mv 15.10 mn 1.180 ma 4.651 cs 1.290 sd 12.62

In Table 7 above, the abbreviation “mv” means “mean diameter in micronsof the “volume distribution” represents the center of gravity of thedistribution. Mie or modified Mie calculations are used to calculate thedistribution. Implementation of the equation used to calculate MV willshow it to be weighted (strongly influenced) by a change in the volumeamount of large particles in the distribution. It is one type of averageparticle size or central tendency”.

The abbreviation “mn” means “mean diameter, in microns, of the “numberdistribution” is calculated using the volume distribution data and isweighted to the smaller particles in the distribution. This type ofaverage is related to population or counting of particles”.

The abbreviation “ma” means “mean diameter, in microns, of the “areadistribution” is calculated from the volume distribution. This area meanis a type average that is less weighted (also less sensitive) than theMV to changes in the amount of coarse particles in the distribution. Itrepresents information on the distribution of surface area of theparticles of the distribution”.

The abbreviation “cs” means “calculated surface—Provided in units ofM²/cc, the value provides an indication of the specific surface area.The CS computation assumes smooth, solid, spherical particles. It may beconverted to classical units for SSA of M²/g by dividing the value bythe density of the particles. It should not be interchanged with BET orother adsorption methods of surface area measurement since CS does nottake into effect porosity of particles, adsorption specificity ortopographical characteristics of particles”.

The abbreviation “cs” means “Standard Deviation in microns, also knownas the Graphic Standard Deviation (σ_(g)), is one measure of the widthof the distribution. It is not an indication of variability for multiplemeasurements. Equation to calculate is: (84%−16%)/2”.

In Table 8 below, the particle size distribution is shown in terms ofpercentile.

TABLE 8 Percentile Value 10% 1.735 20% 3.047 30% 4.638 40% 6.707 50%9.393 60% 13.11 70% 17.92 80% 24.27 90% 35.31 95% 47.68

Table 9 below, the particle size distribution is shown in terms ofparticle size.

TABLE 9 Size (microns) % Pass 704.0-104.7 100.00 95.96 99.74 88.00 99.3680.70 98.99 74.00 98.58 67.86 98.10 62.23 97.54 52.33 96.06 57.06 96.8747.98 95.08 44.00 93.92 40.35 92.55 37.00 90.96 33.93 89.13 31.11 87.0728.53 84.79 26.16 82.31 23.99 79.65 22.00 76.85 20.17 73.97 18.50 71.0716.96 68.18 15.56 65.35 14.27 62.60 13.08 59.92 12.00 57.30 11.00 54.7110.09 52.13 9.250 49.55 8.482 46.96 7.778 44.37 7.133 41.80 6.541 36.835.998 36.83 5.500 34.45 5.044 32.15 4.625 29.93 4.241 27.76 3.889 25.653.566 23.58 3.270 21.58 2.999 19.66 2.750 17.83 2.522 16.12 2.312 14.542.121 13.08 1.945 11.71 1.783 10.41 1.635 9.15 1.499 7.91 1.375 6.691.261 5.49 1.156 4.36 1.060 3.33 0.972 2.44 0.892 1.72 0.818 1.15 0.7500.73 0.688 0.41 0.630 0.16 0.578-0.133 0.00

Example 6

The particle size of hyaloclastite in accordance with the presentinvention was analyzed using a MICROTRAC-X100 light scattering particlessize measuring equipment. The particles were measure in isopropylalcohol, had a reflective index of 1.38, a load factor of 0.0884 and atransmission of 0.86. Table 10 below shows a summary of the particlessize analysis for a hyaloclastite sample wherein 95% by volume of theparticles passed through a 325 mesh screen.

TABLE 10 Property Value mv 8.736 mn 1.488 ma 4.386 cs 1.368 sd 6.136

In Table 11 below, the particle size distribution is shown in terms ofpercentile.

TABLE 11 Percentile Value 10% 1.953 20% 2.962 30% 3.987 40% 5.270 50%6.830 60% 8.682 70% 10.74 80% 13.44 90% 17.74 95% 22.21

Table 12 below, the particle size distribution is shown in terms ofparticle size.

TABLE 12 Size (microns) % Pass 704.0-52.33 100.00 47.98 99.87 44.0099.68 40.35 99.46 37.00 99.20 33.93 98.86 31.11 98.43 28.53 97.87 26.1697.12 23.99 96.13 22.00 94.85 20.17 93.21 18.50 91.16 16.96 88.66 15.5685.75 14.27 82.46 13.08 78.86 12.00 75.05 11.00 71.11 10.09 67.12 9.25063.15 8.482 59.25 7.778 55.45 7.133 51.78 6.541 48.25 5.998 44.86 5.50041.58 5.044 38.39 4.625 35.27 4.241 32.18 3.889 29.13 3.566 26.11 3.27023.18 2.999 20.39 2.750 17.80 2.522 15.46 2.312 13.38 2.121 11.55 1.9459.93 1.783 8.48 1.635 7.15 1.499 5.91 1.375 4.76 1.261 3.69 1.156 2.731.060 1.92 0.972 1.26 0.892 0.77 0.818 0.41 0.750 0.15 0.688-0.133 0.00

It should be understood, of course, that the foregoing relates only tocertain disclosed embodiments of the present invention and that numerousmodifications or alterations may be made therein without departing fromthe spirit and scope of the invention as set forth in the appendedclaims.

What is claimed is:
 1. A mixture comprising: a mineral formed from molten lava or magma that has been quenched by water to form a fragmented, solid mineral, wherein the mineral comprises greater than 69% by weight SiO₂, wherein the mineral comprises approximately 10% to 99% by weight amorphous form and wherein the mineral is reduced in size to a plurality of particles having a volume-based mean particle size of less than or equal to approximately 40 μm, wherein the mineral is hyaloclastite and wherein the plurality of particles have pozzolanic properties; and a hydraulic cement.
 2. The mixture of claim 1, wherein the mineral comprises approximately 15% to approximately 95% by weight amorphous form.
 3. The mixture of claim 1, wherein the mineral comprises approximately 15% to approximately 90% by weight amorphous form.
 4. The mixture of claim 1, wherein the mineral comprises approximately 5% to approximately 20% by weight Al₂O₃.
 5. The mixture of claim 1, wherein the mineral is rhyolitic.
 6. The mixture of claim 1, wherein the mineral has a volume-based mean particle size of less than or equal to approximately 20 μm.
 7. The mixture of claim 1, wherein the mineral has a volume-based mean particle size of less than or equal to approximately 10 μm.
 8. The mixture of claim 1, wherein the mineral comprises approximately 30% to approximately 95% by weight amorphous form.
 9. The mixture of claim 1, wherein the mineral comprises approximately 50% to approximately 95% by weight amorphous form.
 10. The mixture of claim 1, wherein the mineral has a volume-based mean particle size of less than or equal to approximately 5 μm.
 11. A mixture comprising: a mineral formed from molten lava or magma that has been quenched by water to form a fragmented, solid mineral, wherein the mineral comprises greater than 69% by weight SiO₂, wherein the mineral comprises approximately 10% to 99% by weight amorphous form and wherein the mineral is reduced in size to a plurality of particles having a volume-based mean particle size of less than or equal to approximately 40 μm, wherein the mineral is hyaloclastite and wherein the plurality of particles have pozzolanic properties; aggregate; a hydraulic cement; and water sufficient to hydrate the hydraulic cement.
 12. The mixture of claim 11, wherein the mineral comprises approximately 15% to approximately 95% by weight amorphous form.
 13. The mixture of claim 11, wherein the mineral comprises approximately 15% to approximately 90% by weight amorphous form.
 14. The mixture of claim 11, wherein the mineral comprises approximately 5% to approximately 20% by weight Al₂O₃.
 15. The mixture of claim 11, wherein the mineral is rhyolitic.
 16. The mixture of claim 11, wherein the mineral has a volume-based mean particle size of less than or equal to approximately 20 μm.
 17. The mixture of claim 11, wherein the mineral has a volume-based mean particle size of less than or equal to approximately 10 μm.
 18. The mixture of claim 11, wherein the mineral comprises approximately 30% to approximately 95% by weight amorphous form.
 19. The mixture of claim 11, wherein the mineral comprises approximately 50% to approximately 95% by weight amorphous form.
 20. The mixture of claim 11, wherein the mineral has a volume-based mean particle size of less than or equal to approximately 5 μm. 